In vitro trypanocidal evaluation of pinane derivatives from essential oils of ripe fruits from Schinus terebinthifolius Raddi (Anacardiaceae)

Essential oils of ripe fruits from Schinus terebinthifolius (Anacardiaceae), obtained using a pilot extractor and a Clevenger apparatus were chemically characterized. Due the high amount of (-)- α-pinene in both oils, this monoterpene was tested against the protozoan parasite Trypanosoma cruzi, showing a moderate potential (IC50 63.56 µg/mL) when compared to benznidazole (IC50 43.14 µg/mL). Otherwise, (-)- α-pinene oxide did not showed anti-trypanosomal activity (IC50 > 400 µg/mL) while (-)-pinane showed an IC50 of 56.50 µg/mL. The obtained results indicated that the epoxydation of α-pinene results to the loss of the anti-parasitic activity while its hydrogenation product, contributed slightly to the increased activity.

Processo UV/H2O2 como pós-tratamento para remoção de cor e polimento final em efluentes têxteis

Several problems are involved the treatment plants of textile effluents, mainly the low efficiency of color removal. This paper presents an alternative of post-treatment by UV/H2O2 process, for color removal in biologically treated textile effluents. The tests were performed in a photochemical reactor and samples were taken at different times to perform analyses. Using 250 mgH2O2.L-1, 96% removal of color was verified, indicating the dyes degradation. A reduction of 84% of aromatics compounds, 90% of TSS removal, and a further reduction of the organic fraction were observed, demonstrating that the process is effective as a post-treatment of effluents from textile industries.

Degradação de poluentes emergentes por processos Fenton e foto-Fenton

A continuous photochemical treatment system was developed for aiming the treatment of aqueous solutions containing relevant micro-pollutants (microcystin-LR, sulfamethoxazole and 17-b estradiol). The continuous photo-Fenton process provided high degradation efficiency. However, contact time between samples and the irradiated region is short relative to total treatment time, indicating that observed changes are predominantly due to the Fenton process. Higher degradation efficiency was observed in systems operated using two treatment cycles, the first involving a batch Fenton process and the second a continuous photo-Fenton treatment.

Comparação do perfil químico entre cachaças de um mesmo vinho destiladas em alambiques e em colunas

Six wines were distilled in two different distillation apparatus (alembic and column) producing 24 distillates (6 for each alembic fraction - head, heart and tail; 6 column distillates). The chemical composition of distillates from the same wine was determined using chromatographic techniques. Analytical data were subjected to Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) allowing discrimination of four clusters according to chemical profiles. Both distillation processes influenced the sugarcane spirits chemical quality since two types of distillates with different quantitative chemical profiles were produced after the elimination of fermentation step influence.

Efeitos das condições ambientais sobre o teor e variabilidade dos óleos voláteis de dalbergia frutescens (Vell.) Britton (Fabaceae)

The volatile oils of Dalbergia frutescens were obtained by hydrodistillation on a Clevenger-modified apparatus for every month of one year and assessed on GC/MS and GC/FID detectors for qualitative and quantitative analyses. The influence on content of volatile oils was directly proportional to the environmental variables, temperature and cloudiness, and inversely proportional to precipitation. Among the volatile compounds detected, linalool, β-damascenone, α-ionone, geranyl acetone and β-ionone were the main components, of which β-damascenone and β-ionone were found at the highest concentrations.

Avaliação de furanocumarinas como inibidores da fotossíntese através de ensaios de fluorescência da clorofila a

The evaluations of Chorophyll a fluorescence emitted by superior plants carry structural information and photosynthetic apparatus function. Quantitative analysis apparatus of fluorescence kinetic were measured by energy flows (ABS), (TR), (ET) and (DI), known as phenomenological phenomena of OJIP test. Four furocoumarins were isolated from Ruta graveolens (Rutaceae), and chorophyll a (Chl a) fluorescence assays were performed with these compounds to evaluate the photosynthesis inhibition potential. This test was realized in spinach`s leaf discs and in Lolium perenne leaves. The results indicated the herbicide potential mainly for bergapten and chalepin.

Equipamento de baixo custo para extração em fase sólida em amostras aquosas de grande volume utilizando pressão positiva de N

Extraction/concentration is a crucial step for the analysis of organic compounds at trace level concentrations and dispersed in complex matrices. Solid-phase extraction (SPE) is one of the techniques used for this purpose. In this work, a low cost apparatus for SPE was developed that uses nitrogen under positive pressure and ensures the maintenance of the sample flow, while also allows the simultaneous extraction of different samples without cross-contamination and sample contact with plastic materials. For the system set up, easily accessible materials were used such as hypodermic needles, stainless steel tubes, rubber stoppers, and 3-way valves from serum delivery apparatus.

Um reator fotoquímico barato e eficiente para experimentos de química

In this work, we present an efficient and inexpensive device for undergraduate chemistry classes aimed at teaching and learning the photolytic synthesis concepts. A photochemical reactor was tested for the synthesis of the organometallic compound enneacarbonyldiiron from iron pentacarbonyl in acetic acid, and its formation evidenced by FTIR analysis. Although similar devices have been described in other studies, none of these offered the simplicity, low cost, class-compatible reaction times and good yields afforded by the procedure reported herein.

Aplicação da radiação ultravioleta como forma de contribuição para a química verde e construção de um reator fotoquímico alternativo e de baixo custo, para pré-tratamento de amostras

Ultraviolet radiation corresponds to a fraction of electromagnetic radiation, covering wavelengths between 1 and 400 nm. Methods based on UV irradiation have become popular because it is possible to treat samples simply by applying energy, avoiding procedures that require the use of toxic substances, thus contributing to the development of Green Chemistry. This study aimed to assess the main applications of UV radiation reported in the literature and thoroughly described the construction of an alternative and low-cost photochemical reactor to be used for the pretreatment of samples in the laboratory. The use of this new photochemical reactor in the clean-up of milk samples for spectrofluorimetric measurements was also reported.

Variation of essential oil composition of Tapirira guianensis Aubl. (Anacardiaceae) from two sandbank forests, north of Brazil

Tapirira guianensis (Anacardiaceae) is used in traditional medicine and is important for the recovery of degraded areas and riparian forests because the T. guianensis fruits are highly consumed by wildlife. Volatile components from dried leaves and branches of five individual plants of T. guianensis were collected in two sandbank forests of the State of Pará (Extractive Reserve Maracanã and Area of Environmental Protection Algodoal/Maiandeua), extracted by hydrodistillation using a Clevenger-type apparatus, and analyzed by GC/MS. The ten oils obtained are comprised mostly of sesquiterpene hydrocarbons (58.49 to 100%), with (E)-caryophyllene, β-selinene, α-selinene, β-sesquiphellandrene, and α-zingiberene being the most prominent. The results of the oil compositions were processed by Hierarchical Component Analysis (HCA) allowing the establishment of three groups of essential oils for T. guianensis differentiated by the content of β-selinene/α-selinene (Type I), (E)-caryophyllene (Type II), and β-sesquiphellandrene/α-zingiberene (Type III).

O USO DE UM SENSOR DE LUZ LINEAR COMO RECURSO DIDÁTICO PARA DEMONSTRAR PRINCÍPIOS DE DIFRAÇÃO E ESPECTROSCOPIA

This article presents a discussion on light diffraction by slits and grids as well as the development of an experimental apparatus which provides quantitative observation of the phenomenon. We conducted a brief historical survey on the evolution of the wave theory of light and the role of diffraction in the context of optical spectroscopy. We also reviewed the use of Huygens’ principle to calculate the intensity pattern obtained when light is diffracted by slits and compared the predictions with experimental results obtained using the apparatus developed. Finally, the use of the apparatus in an optical spectroscopy experiment was demonstrated.

Sugarcane yellow leaf virus infection leads to alterations in photosynthetic efficiency and carbohydrate accumulation in sugarcane leaves

Infection by Sugarcane yellow leaf virus (ScYLV) causes severe leaf symptoms in sugarcane (Saccharum spp.) hybrids, which indicate alterations in its photosynthetic apparatus. To gain an overview of the physiological status of infected plants, we evaluated chlorophyll a fluorescence and gas exchange assays, correlating the results with leaf metabolic surveys, i.e., photosynthetic pigments and carbohydrate contents. When compared to healthy plants, infected plants showed a reduction in potential quantum efficiency for photochemistry of photosystem (PSII) and alterations in the filling up of the plastoquinone (PQ) pool. They also showed reduction in the CO2 net exchange rates, probably as a consequence of impaired quantum yield. In addition, reductions were found in the contents of photosynthetic leaf pigments and in the ratio chlorophyll a/chlorophyll b (chla/chlb). Carbohydrate content in the leaves was increased as a secondary effect of the ScYLV infection. This article discusses the relation of virus replication and host defense responses with general alterations in the photosynthetic apparatus and in the metabolism of infected plants.

Comparison Structure Analysis

This study presents an automatic, computer-aided analytical method called Comparison Structure Analysis (CSA), which can be applied to different dimensions of music. The aim of CSA is first and foremost practical: to produce dynamic and understandable representations of musical properties by evaluating the prevalence of a chosen musical data structure through a musical piece. Such a comparison structure may refer to a mathematical vector, a set, a matrix or another type of data structure and even a combination of data structures. CSA depends on an abstract systematic segmentation that allows for a statistical or mathematical survey of the data. To choose a comparison structure is to tune the apparatus to be sensitive to an exclusive set of musical properties. CSA settles somewhere between traditional music analysis and computer aided music information retrieval (MIR). Theoretically defined musical entities, such as pitch-class sets, set-classes and particular rhythm patterns are detected in compositions using pattern extraction and pattern comparison algorithms that are typical within the field of MIR. In principle, the idea of comparison structure analysis can be applied to any time-series type data and, in the music analytical context, to polyphonic as well as homophonic music. Tonal trends, set-class similarities, invertible counterpoints, voice-leading similarities, short-term modulations, rhythmic similarities and multiparametric changes in musical texture were studied. Since CSA allows for a highly accurate classification of compositions, its methods may be applicable to symbolic music information retrieval as well. The strength of CSA relies especially on the possibility to make comparisons between the observations concerning different musical parameters and to combine it with statistical and perhaps other music analytical methods. The results of CSA are dependent on the competence of the similarity measure. New similarity measures for tonal stability, rhythmic and set-class similarity measurements were proposed. The most advanced results were attained by employing the automated function generation – comparable with the so-called genetic programming – to search for an optimal model for set-class similarity measurements. However, the results of CSA seem to agree strongly, independent of the type of similarity function employed in the analysis.

Photoinhibition of Photosystem II. Kinetics, Photoprotection and Mechanism

Photosystem II (PSII) is susceptible to light-induced damage defined as photoinhibition. In natural conditions, plants are capable of repairing the photoinhibited PSII by on-going degradation and re-synthesis of the D1 reaction centre protein of PSII. Photoinhibition is induced by both visible and ultraviolet light and photoinhibition occurs under all light intensities with the same efficiency per photon. In my thesis work, I studied the reaction kinetics and mechanism of photoinhibition of PSII, as well as photoprotection in leaves of higher plants. Action spectroscopy was used to identify photoreceptors of photoinhibition. I found that the action spectrum of photoinhibition in vivo shows resemblance to the absorption spectra of manganese model compounds of the oxygen evolving complex (OEC) suggesting a role for manganese as a photoreceptor of photoinhibition under UV and visible light. In order to study the protective effect of non-photochemical quenching, the action spectrum was measured from leaves of wild type Arabidopsis thaliana and two mutants impaired in nonphotochemical quenching of chlorophyll a excitations. The findings of action spectroscopy and simulations of chlorophyll-based photoinhibition mechanisms suggested that quenching of antenna excitations protects less efficiently than would be expected if antenna chlorophylls were the only photoreceptors of photoinhibition. The reaction kinetics of prolonged photoinhibition was studied in leaves of Cucurbita maxima and Capsicum annuum. The results indicated that photoinhibitory decrease in both the oxygen evolution activity and ratio of variable to maximum fluorescence follows firstorder kinetics in vivo. The persistence of first-order kinetics suggests that already photoinhibited reaction centres do not protect against photoinhibition and that the mechanism of photoinhibition does not have a reversible intermediate. When Cucurbita maxima leaves were photoinhibited with saturating single-turnover flashes and continuous light, the light response curve of photoinhibition was found to be essentially a straight line with both types of illumination, suggesting that similar photoinhibition mechanisms might function during illumination with continuous light and during illumination with short flashes.

Kuivurin pölynhallintajärjestelmä

Lämminilmakuivaus on viljan kuivaamisen menetelmistä ylivoimaisesti käytetyin. Siinä kuivurissa olevan viljakerroksen läpi puhalletaan lämmintä ilmaa, kunnes viljan kosteuspitoisuus laskee tavoitetasoon. Viljan jyvistä irtoaa aina pölyä niiden hangatessa toisiaan vasten. Viljankuivaamoiden pölyisyyttä on normaalisti pyritty vähentämään poistamalla leijuvaa pölyä viljan liikkeen epäjatkuvuuskohdista. Pölyä kulkeutuu kuitenkin kuivaamon ulkopuolelle myös kuivaukseen käytetyn ilman mukana. Poistoilman pölypitoisuus ei tavallisesti ole korkea, mutta kuivaamiseen käytetyistä suurista ilmamääristä johtuen pölyä voi kertyä poistoilmakanavan ympäristöön huomattavia määriä. Tämän diplomityön tavoitteena onkin viljankuivurin poistoilman pölypitoisuuden vähentämiseen soveltuvan pölynhallintajärjestelmän kehittäminen. Selvityksessä tarkasteltiin ensinnäkin kuivurin poistoilman pölypitoisuuteen liittyvää kansallista ja kansainvälistä lainsäädäntöä sekä raja-arvoja. Lähdemateriaalin perusteella kartoitettiin pölypitoisuuden vähentämiseen soveltuvia menetelmiä sekä kilpailijoiden toteuttamia ratkaisuja. Myös muita pölynhallintajärjestelmän edellytyksiä selvitettiin. Teoreettisessa tarkastelussa teknistaloudellisesti parhaaksi osoittautunut pölynhallintaratkaisu jalostettiin prototyypiksi. Sen toimintakykyä testattiin erotustehokkuuden mittaamiseen soveltuvan koelaitteiston avulla. Testitulosten perusteella kyseinen pölynhallintajärjestelmä todettiin toimivaksi ja pienellä jatkokehittelyllä myös kaupalliseen käyttöön soveltuvaksi. Testitulosten hyödyntämismahdollisuuksien lisäksi diplomityössä esitetään myös muutamia jatkokehitysehdotuksia.